Have you ever wondered how close you should be sitting to your computer screen? When you are setting up your workstation there are guidelines and suggestions for your monitor placement and lighting. The following recommendations are based on the latest scientific research found on www.office-ergo.com.
Eye to screen distance
You should locate your monitor at least 25 inches from the eyes, preferably more. One of the main reasons for computer related eyestrain is the closeness of the monitor. The farther away your monitor, the less strain there is on your eyes.
The entire viewing area of the monitor should be located between 15° and 50° below horizontal eye level. While the eyes might be most comfortable with a 15° gaze angle when looking at distant objects, for close objects they prefer a much more downward gaze angle. Lower monitor placement also exposes less of the eyeball to the atmosphere and reduces the rate of tear evaporation. This keeps the eyes more moist and reduces the risk of Dry Eye Syndrome.
Early recommendations said that the distance from monitor to hard copy had to be the same. But to do that often means moving the monitor closer. Recent research has found that eyestrain was not increased when the monitor and document distance differed. In fact, users preferred that the monitor be farther away. For data entry tasks that require rapid shifts from screen to document, locating the screen and document at similar distances can reduce the time lag encountered when changing accommodation. In this case enlarging the document is the best solution. The larger letters will then be visible at the greater viewing distance.
Lower monitor placement can increase the acceptable options that users have for neck movement. Eye-level monitors allow the head and neck to assume only one posture that is both visually and posturally comfortable. It can be uncomfortable to maintain the same posture for an extended period of time. When users tire of the head-erect posture, the acceptable alternative postures with eye level monitor are limited. Flexing the neck is one alternative, but that results in the user looking out of the top of their eyes. With a low monitor position you can hold your head erect and look downward. When that posture becomes tiring, a low monitor will allow you to alternate among a wide range of flexed neck postures that allow good visual performance and will not increase postural discomfort as long as you don’t hold any particular posture for too long.
It is best to tilt the monitor back so that the top is slightly farther away form the eyes than the bottom. When we look at the world, objects in the upper part of our peripheral vision are generally farther away than the point we are looking at, and objects in the lower part of our peripheral vision are usually closer. As a result, our visual system has developed to perform best when the visual plane tilts away from us at the top.
Tilting a monitor down, as is sometimes done to avoid glare, is opposite of the capabilities of the visual system. Tilting the monitor downward will often lead to increased visual and postural discomfort.
In an office of any size, the best solution for glare and reflections on the screen, as well as for overall visual performance, is ceiling suspended, indirect lighting. Because some tasks and workers require more light than others, it is bet to keep the overall light level low and allow workers to supplement it with individually controlled task lights.
It is recommended that you use dark letters on a light background. A light background will reduce the difference in contrast between the screen and what is reflected off of it. A white background also reduces the luminance (brightness) difference between the screen and the surrounding background of a normally lighted office. That makes it easier on your eyes!
Hopefully you have learned something new from these guidelines. I plan to make a few changes to my workstation to see if I can become more productive with less discomfort.